The present invention relates to an automatic transmission using a gear-type shifting means, and to an automobile using the gear-type automatic transmission.
Prior inventions relating to an automatic transmission using a gear-type shifting means include one in which the top-speed gear of the gear-type automatic transmission is engaged/disengaged using a multi-disc clutch and when a shift is performed, the engine speed of the corresponding vehicle is controlled by slipping the multi-disc clutch and is thus synchronized with the rotational speed of the output shaft so as to accomplish the shift smoothly. Such prior art is disclosed in, for example, Japanese Laid-Open Patent Application Publication No. Sho 61-45163.
The gear-type automatic transmission described above, however, poses the problems that if the torque capacity of the multi-disc clutch is small, when a shift is made at a high output shaft torque, the difference between this torque and the torque that the multi-disc clutch can generate will be transmitted to the output shaft as a change in torque, thus making the passengers (including the driver) feel uncomfortable, and that in case of trouble with the driving source of the actuators which drive the automatic transmission, if the engine torque is not transmitted to the output shaft properly, this can cause the engine to stall or the engine speed to increase abruptly, thus resulting in the vehicle not operating properly.
The present invention provides: a gear-type automatic transmission that enables smooth shifts to be performed by varying the output shaft torque of the automatic transmission smoothly, even when the output shaft torque is high, and the corresponding vehicle to run properly, even if any trouble occurs in the driving source of the actuators which drive the automatic transmission; and an automobile that uses the gear-type automatic transmission.
The present invention relates to a gear-type automatic transmission having a plurality of gear trains between its input shaft and output shaft and capable of changing the revolutions of said input shaft and output shaft by repeating selective and automatic engagement and disengagement of said gear trains, wherein the gear-type automatic transmission further has a clutch that temporarily transmits the torque of the input shaft and output shaft when shifting one of the gear trains to another gear train.